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it is the mechanical behaviour of the wire that change depending of the level of stress it is subjected to. This was examined by acousticians and physicians before piano technicians begin to think of "rescaling"

this is something about how the elastic energy stocked within the wire behave

Edited by Olek (01/25/1301:08 PM)

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it is the mechanical behaviour of the wire that change depending of the level of stress it is subjected to. This was examined by acousticians and physicians before piano technicians begin to think of "rescaling"

this is something about how the elastic energy stocked within the wire behave

BTW the piano string tone is characterized by a "double decreasing" , it seem to be common term in the literature.Coupling on a moving bridge make polarization on both planes, hence beats or double decreasing of the partials.

WHile this paraameter is evident to anyone listening well I cannot understand why it is never/rarely explained in the unison tuning descriptions.

Most of the descriptions I see talk of total coupling, like if the sound could be "on" or "off" and beats an absolute evil.

A single string is producing some sort of beat by itself, due to the way it behave.

That beat can be fight or used while tuning. when tuning 2 strings coupling via the bridge the tuner may modify the delay before horizontal polarization, or something similar ...

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This question about the stiffness of piano wire, as it would have been when new on old pianos, brings up a broader issue for me.

Among the best scaled pianos of the world today, are they using the differing types of wire which are itemized in the Paulello Typogram as X,M,O,1,and 2 ? Isaac has replied that he personally spoke with one German company that does. This lends credibility.[Correction: Isaac corrected me to clarify: The manufacturer tended to use the same wire, but use the higher tensions with hard wire to achieve a closer approach to the yield point of that wire. That is an agreement with the theory related to yield point, but not an agreement with the value of using modified wire.]

In America, I would suspect that Mason & Hamlin might have gone into research on this as they reworked their classic designs and resurrected them for production. Does anyone have information on M&H or other companies in relation to this. The basic issue seems to be whether the very minute choices as to alloy and tempering (as they pertain to yield strength) are worthwhile in establishing the very foundation of tone.

If these fine choices are legitimate, then one would logically follow this path, if trying to change and improve an old scale: [This would not apply to Craig, since his objective is original scale and original personality of the instrument.]1. Measure, then generate the new scale.2. Analyze via the Paulello T.3. String the piano with the wire giving the desired %. This would involve several types of wire across the scale.I think that this discussion has basically concluded that the tension of the wire in that scale would not be where the change would lie. The change would be how close the strings would be, at tuned tension, to their yield point.

Phil no manufacturer I talk with use different stiffness wire they all use Roslau anx there is no choice, one stiffness only.

I just talked with one about the level of constrain/stress the wire is submited to and was said it was an important parameter (not the only one) .Well I will say it, it was Mr Sauter who told me they attain 80% of the strain in the mediums, where usually we are with more moderate strain (but I have seen old scales with such strain in the mediums, depite soft wire)

Since then it is a mistery to me, as too much stress is as bad for the tone than not enough. That said the Sauter pianos have a high tension scale and their medium is very "fast" and crisp.

It is just that I will not be surprized now if I find such high level of stress on a scale. (that did not happen and I did not have the chance to see a Sauter scale so my witnessing is good for what is worth, please dont misunderstand me ...

In those older times the same thing happens, only one quality of wire was used at a time in a factory ,eventually the bass strings can be wound on another wire if the bass maker is external to the factory and he used Poehlmann wire for instance , when the factory use Roslau (both existed for some time) or other brand of wire as they where present in the beginning of 1900, slowly stopping production until one only remains (and piano wire is 3% or 5% or the production of the wire maker )

Paulello stress us to use different type of wire, insisting on the advantage of an even progression of the constrain.

It is related to relatively recent work from theoricians, but for instance Paulello wire and Roslau wire have a different spectra and enveloppe so if you begin to mix types you better use the same product on the whole piano, I have mixed types, Paulello and Roslau, the transition may happen at a plate break and I may think "registers" if not the change in spectra is somehow noticeable.

Paulello scales are very smooth in progression, having soft wire to raise the level of strain on the first plain wire (often under 40%BS if you use Roslau) is of some help.

Then I use mostly Roslau that seem to bring a different fundamental to partials ratio and a more evolving enveloppe.

If the piano you have used softer wire, you have no much choice, Roslau strings in the mediums if under 40% is really awful and nasal.

There is a nickel plated version of Paulello wire, that may have a different spectra, I understnd the W&L producer use them in their "Feurich" line of products , for the treble.

In the treble, you will see that most pianos need or may accept modern wire as Roslau or Paulello M.

As it was written above, as the scale is "set" even if you lower the tension, oor raise it, you will not change the BS percentage much.

If you want to use modern wire, you may prefer to lower the wire gauge so the tension and iH lower.

For instance theiH on the A4 of a 1920 Pleyel could be 6.5 originally (yet high) if you keep the diameter hence tension it raise to 7.2 with Roslau wire.

if you lower the tension using 2 jauge less you will attain 6.6 but the tone will be less powerful.

The BS percentage lower if you mix wire types, what change at the same time is the elongation of the wire, this parameter is very important for the tuning to stay put when the piano is submitted to heat, dryness, etc...

Edited by Olek (01/26/1309:57 AM)

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old pianos have often not the raise in tension we see in the modern ones, lot of tension in the low mediums as soon as possible, then a smooth slant of tension lowering. Modern pianos have a raise in tension in the last treble section (from which note ?)

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As older builders had only access to one wire quality at a time, I suggest that at last one may analize the scale for tension iH and BS yeld stretch(I always forget that term)

Most old German pianos can use modern wireOld French pianos (and not so old) used "Firminy wire" for most of them.This wire is softer than Roslau, but strangely seem to have an excellent breakin strain level.

If your old scale have enough tension allowed you have no real problems , only choices between more iH and less iH.

If the scale is for instance a 50 Kg scale you may need soft wire.In that case it cannot be bad to mix the types.idem for the basses, the first basses have a low level of yesd stretch usually , if you lower it even more by using stiffer wire, the basses will be more inharmonic, not avery good choice.

But our bass makers know how to obtain good basses in many cases, for instance using methods known as TF65.to detremine the thicknesses.

I would not be surprised if some of the pianos at the turn of 1900 used high carbon content wire. I have heard some old Bechstein that had visibly a wire producing way more iH than Roslau, it can be perceived despite time (?)

I just read when looking for information on those yeld stretch parameters, that the piano wire is not annealed a lot at the moment it is mounted in the instrument, and that the annealing is finished with the help of the tension.

This may possibly relate to the yesld strech ratio in some way...

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I just read when looking for information on those yeld stretch parameters, that the piano wire is not annealed a lot at the moment it is mounted in the instrument, and that the annealing is finished with the help of the tension.

Isaac,Here, did you mean to say that the tempering is finished by the tension, rather than annealing (softening)? Normally the process is ...a) anneal, meaning to heat then slowly cool in controlled fashionb) harden,meaning to heat, then cool quickly in oil or other liquid c) temper, meaning to evenly heat to a set temperature for a set amount of time, according to the work purpose of the metal

Clawing and scratching at the back of my mind has been this practical consideration: I can imagine that specialty wire shipped from Italy - not exactly a country known for competition and high efficiency in business of late - would cost at least four times the cost of commonly available Mapes or Schaff wire, and probably much, much more that Roslau.

I just read when looking for information on those yeld stretch parameters, that the piano wire is not annealed a lot at the moment it is mounted in the instrument, and that the annealing is finished with the help of the tension.

Isaac,Here, did you mean to say that the tempering is finished by the tension, rather than annealing (softening)? Normally the process is ...a) anneal, b) harden, c) temper.

Thanks for correcting me. I have to check again, but the sence was hardened, hence temper.

Then each new pass in the wire making machine harden the steel, to the point it have to be passed in a hot bath so the steel is soft and can be made thinner. That is the process , I suppose that no hardening is done by cooking , tha annealing create a harder layer around the core of the wire. The bath is a lead bath..

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Lead melts at 621F, but doesn't boil until over 3100F. Due to that wide range of possible temperatures for a lead bath, it could definitely be used to soften wire between drawing/machining stages. FIB Belgium is a supplier of such equipment, using a double vessel lead bath setup. SOLO in Switzerland is another. Since tempering temperatures for carbon steel range from around 400F to 640F, the lead bath could not be used for tempering, except at the "blue" end of the color range - that being a considerable amount of tempering. When you heat too far beyond the blue range, you are getting closer to annealing again - not useful for piano wire.

The later stage - tempering - takes quenched wire from that brittle stage and softens it slightly, leaving it more useful, flexible, but remaining hard to the degree desirable for the use of that metal. One could think of it as partial re-softening (but more complicated than that). In the case of piano wire, it is imaginable to me that a wire softened through tempering to a given point would then, as it stretched under tension, regain a little hardness/stiffness.

I will try to add to my earlier notation to include this. (Any metallurgical engineers, feel free to jump in here. I have only known one guy with that particular degree.)

So, as a comparison, these specialty wires cost about two and a half times what Mapes Gold or Roslau cost. And Roslau is only 5-6% more than Mapes. That is comparing 1-pound rolls of those two brands coming from Schaff Piano Supply.

Lead melts at 621F, but doesn't boil until over 3100F. Due to that wide range of possible temperatures for a lead bath, it could definitely be used to soften wire between drawing/machining stages. FIB Belgium is a supplier of such equipment, using a double vessel lead bath setup. SOLO in Switzerland is another. Since tempering temperatures for carbon steel range from around 400F to 640F, the lead bath could not be used for tempering, except at the "blue" end of the color range - that being a considerable amount of tempering. When you heat too far beyond the blue range, you are getting closer to annealing again - not useful for piano wire.

The later stage - tempering - takes quenched wire from that brittle stage and softens it slightly, leaving it more useful, flexible, but remaining hard to the degree desirable for the use of that metal. One could think of it as partial re-softening (but more complicated than that). In the case of piano wire, it is imaginable to me that a wire softened through tempering to a given point would then, as it stretched under tension, regain a little hardness/stiffness.

I will try to add to my earlier notation to include this. (Any metallurgical engineers, feel free to jump in here. I have only known one guy with that particular degree.)

Thank you, it was the first time I have seen written that the wire harden due to tension. We experiment the evolving of tone between new installed string and the same, massaged (strongly with a hard wooden block and preferently to produce some heat I was said , from a respected high level string's specialist - but it could be just an old trick without good effects on tone)

after a few pitch raise and tunings the tone is very different and begin to be nice, let's say a few days after stringing.

Knowing that some metallurgical process happens then that change the consistency of the wire, allow to experiment.

I once used the maximum over pull on new wire (raising so to be nearer of the grey zone before plasticity, then leaving the wire that way for 8 hours, and tune back to normal pitch.

The result was a very clear tone, with more partials.A little thin may be. possibly more iH.

I regret I did not measure iH before and after, but I will, that experiment is easy to realize, the bridge pins must be in good condition indeed.

It was some time ago. Now I would recognize if iH raise or lower. and I will measure it with Tunelab, measuring with tunelab allows to see the iH changing with a small pitch change (4 Hz for instance) so it may be enough to measure.

I can obtain another tool more oriented to iH analysis, also

Edited by Olek (01/26/1303:52 PM)

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I read through the literature about Paulello wire, and realized that whether it is historically accurate or not depends on how you define historical accuracy. There is no way on earth than any of the early piano makers would have known, let alone cared about the factors that Paulello uses to distinguish the types of wire that they make. Probably the only thing they cared about was whether it broke or not, and how much it cost. By that criterion, the most historically accurate wire would be the modern wire that is used in manufacturing pianos today, because it has a higher breaking strength and costs less.

The idea is basically to have a low enough iH, then if some new parameters allow to have a more smooth tone progression, why not ?

But I suggest that one must be able to imagine what he is after, and also to take in account all the availeable ^parameters.

I have heard Japanes wire and find it more sounding as the old type French wire than Roslau.

I have heard old Poeehlmann wire and find it better than actual Roslau

I have heard that the speed used on the actual drawing process is controversial to wire quality, that the availeable steel of today is less pure than what was availeable 40 years ago, and all sort of ideas and methods to evaluate a scale.

I have learned to replace all the old pianos strings with a similar diameter wireThen to replace all the strings by a wire one size lessThen to measure and compute the tension (or use the Booklet made by Klaus Fenner, trying to avoid jumps and hops in tension if any)

Then I have begin to be able to notice how a newly stringed old piano have often not much of the warmness it have originally

Pure wire (stainless steel wire) then Paulello, have helped at last to have a better iH on the stringed pianos.

That mean the tone is very brillant, partials are more together than with usual iH (think Fazioli for instance)On the other side, there is some sort of unbalance and the energy spend for the partials may sound missing for the fundamental.The double decreasing noticed usually have avery differnt shape, so the voicing may be very different if you want to have enough fundamental

Dynamic of the tone is more reduced or gives the impression to be. It can be heard yet listening to French pianos recordings from the 1950 era. SOme Pleyel, some gaveau, the tone is way less "greasy" than the german tone.

Historical is a totally different approach and impossible to realize today, possibly on Forte pianos we will have some very good phosphorous iron wire, that is said to correspond to the wire used at those times.

But till 1840 +- all makers where using steel wire, with different tensile strain depending of the era hence different levels of iH (and power)

We where lucky in France as the Firminy wire (type O Paulello) was sold till 1965, so from time to time I meet a French piano that have been re stringed with that exact wire (which can be verified because there are more gauges for the low medium range)

The tone quality of those instruments is simply not available today, too different from our actual standards.

I also heard old Erards with their original wire and a so nice, singing and mellow tone, the same mounted with Roslau are interesting.

The 1960 quality was certainly different from the one of 1930 , but still the impact of wire on the tone of the piano is probably as large as the one of the soundboard (and the hammers).

Wire is the engine, in the end, the rest is just there to drive it or to use the result of the vibes.

Now I find much easier to repair old German pianos due to their high tension scale.

BTW you where right about the BS% not changing noticeably with gauge change.

It is very interesting to analyse the original scaling progression using the breaking strain data available and real gauges.

Some of those old scales (Pleyel for instance) where really excellent. Pleyel worked for quite some time with Gustave Lyons, a physicist and acoustical engineer,(designed the Pleyel concert hall in Paris) that made huge improvements to the instrument.

Edited by Olek (01/26/1305:05 PM)

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Probably, but what doe sit mean, they tested which size of wire gave the best tone, or which tension was best ?

Without iH computation there are enough other parameters available to them.

I agree iH is a result of parameters , it is a tool for us and hopefully we know what it is and how to try to evaluate it beforehand.

But that does not mean it is not a characteristic of a given scale.

Thos "low tension, high tension scale" are yet styles used when a piano is designed, as said manufacturers (without telling you too much about the details)

Klaus Fenner produced a "bible" resuming the evolving and differnt styles in use today - if I would spend as much time as I write on that forum (I am ill and cannot work since a few days) learning German I would have read and understood that book yet

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If you look at scales of pre-1900 period, you come to realize that pianos were designed so that strings were somehow fit into them, and then wire gauges were tried according to the customs of the time. The scales are never very good.

After around WWI, you see some scales that actually seemed to be designed according to some principles. Tensions become more uniform and logical. Still, most of them paid homage to the customs of previous times, though.

I have to agree that most of the older scales are uneven. That is not necessarily limited to pianos that are very old. Seldom have I used exactly the same gauges on a restoration, and I regret some choices to go original.

We can readily see that the OP's situation is one in which he is not free to do this, since the owner has requested originality. I believe the sound board may prevent the result the customer desires: to hear the piano as it sounded new.

"The yield point varies not only for the particular grade of steel, but also its temper. Many people don't realize that the tempering process only affects the yield point, but not the modulus. So, basically, all wire that would be suitable for piano strings has essentially the same stiffness, and the same density--it is really only the yield point that varies. Does variation in yield strength really affect sound. Well, I'm skeptical. Remember that all piano wire is tensioned well below the yield point."

Experience using lower Break Point, (BP) high-carbon, (HC) piano wire on pianos does show an audible difference. The only logical explanation for this is the internal damping of the softer wire upon longitudinal mode, (L-Mode).

The Pure Sound stainless alloy wire shows a further reduction in L-mode over HC wire.

Data for this can be found in the book published by the Piano Technicians Guild authored by James Ellis about L-mode in taut piano strings. He used his test monochord outfitted with magnetostrictive transducers to measure L-mode frequency and relative amplitude of several types of piano wire including Pure Sound.

Many technicians are now developing protocols to modify wire types where the portion of a pianos scale reaches relatively lo BP. This is to improve the tone where the scale break occurs between plain and wound strings.

The advantage of the "softer" wires is you can maintain and even introduce more tri-chord and bi-chord unisons into a scale to make fuller use of the unison coupling between three strings which produce a deeper tone compared to bi-chord coupling.

Also L-mode is louder and more evident when the angle the strings make where they cross the bridge is close to a right angle. This is why the hockey -stick low tenor bridge can howl especially when carrying wound strings. The rocking bridge motion reinforces or reignites L-mode in the string. These L-modes can couple into and out of the Transverse modes in some very complex ways which Ellis's excellent work has shed some much needed light on.

I have to agree that most of the older scales are uneven. That is not necessarily limited to pianos that are very old. Seldom have I used exactly the same gauges on a restoration, and I regret some choices to go original.

We can readily see that the OP's situation is one in which he is not free to do this, since the owner has requested originality. I believe the sound board may prevent the result the customer desires: to hear the piano as it sounded new.

It could be that they did not have all the wanted jauges, or that they think in term of registers. It is normal to try to use the wire we have availeable in the best possible way.

Moderate progression of tension, for instance, but unless strings lenght are modified our options are limited.

There are visibly different ways to apprehend scaling . Possibly some makers used to push one parameter at the expense if another (I think of power mostly)

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It is critical that you call your Senators and Representatives and ask them to cosponsor S. 2587 and H.R. 5052. Getting your legislators to cosponsor these bills

I have to agree that most of the older scales are uneven. That is not necessarily limited to pianos that are very old. Seldom have I used exactly the same gauges on a restoration, and I regret some choices to go original.

We can readily see that the OP's situation is one in which he is not free to do this, since the owner has requested originality. I believe the sound board may prevent the result the customer desires: to hear the piano as it sounded new.

It could be that they did not have all the wanted jauges, or that they think in term of registers. It is normal to try to use the wire we have availeable in the best possible way.

Moderate progression of tension, for instance, but unless strings lenght are modified our options are limited.

There are visibly different ways to apprehend scaling . Possibly some makers used to push one parameter at the expense of another (I think of power mostly)

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It is critical that you call your Senators and Representatives and ask them to cosponsor S. 2587 and H.R. 5052. Getting your legislators to cosponsor these bills